Post-it notes are a mixed blessing. They can seem oh-so-handy for adding notes to files, flagging salient points in a document, or scribbling down notes while you're on the phone. But they can be a curse if they get lost or moved; and all too often they're misused or overused. If you want to keep the information and be able to track or file it, don't place it in a post-it. It's no good saying "I noted that on the file!" if you did so on a post-it which has since disappeared. Post-its also making copying paper files a pain - to be thorough you have to copy the document with and without the post-it, and that's a waste of time. I freely admit I'm a post-it junkie. I'm trying to curb my usage. In that spirit, here's a link to some nice photos of artists making better use of post-its!
Productivity in many colors [Color + Design Blog]